The semiconductor integrated circuit (IC) industry has experienced rapid growth. In the course of IC evolution, functional density (i.e., the number of interconnected devices per chip area) has generally increased while geometry size (i.e., the smallest component (or line) that can be created using a fabrication process) has decreased. This scaling down process generally provides benefits by increasing production efficiency and lowering associated costs. Such scaling down has also increased the complexity of processing and manufacturing ICs and, for these advances to be realized, similar developments in IC manufacturing are needed.
For example, in semiconductor technologies, a plurality of photomasks (masks) are formed with predesigned IC patterns. The plurality of masks are used during lithography processes to transfer the predesigned IC patterns to multiple semiconductor wafers. As such, photomask must be substantially devoid of foreign particles during the lithography process. Commonly, photomasks are transported between stations in a semiconductor fabrication facility inside of a transportation/storage pod. Some types of photomasks are protected by pellicles during transportation, however, other types of photomasks—such as masks used for EUV (extreme ultraviolet) lithography—may not be protectable by pellicles. Further, EUV photomasks may be more sensitive to contamination because of smaller feature size. Thus, in some cases, foreign particles attached to the inside of a pod may transfer a photomask during transportation. Accordingly, it may be desirable to thoroughly clean a photomask pod before it is used to transport a photomask. However, it may be difficult to determine if a pod is substantially free of foreign particles after a cleaning. Thus, although existing systems and approaches have been satisfactory for their intended purposes, they have not been entirely satisfactory in all respects.